Press with a hydraulic plate

ABSTRACT

The invention concerns a press, in particular, a precision blanking press, with a slide (1) and a press lower part (3) associated with the slide, a tool (17) being located between the slide (1) and the press lower part (3). According to the invention, a hydraulic plate (9, 10) is disposed between an upper tool and the slide (1) and/or a lower tool and the press lower part (3).

This application is a 371 of PCT/EP97/01303, filed Mar. 14, 1997.

The invention relates to a press, in particular a precision blankingpress, with a press upper part and a press lower part associated withthe press upper part, a tool being located between the press upper partand press lower part and a hydraulic plate being arranged between anupper tool and the press upper part and/or a lower tool and the presslower part.

Various forms and designs of presses are commercially available. As arule, a press punches out a workpiece from a workpiece strip, forexample, and the corresponding tool machines it in the press, forexample folds it or the like. During the machining of the workpiece, aplurality of tool elements interact, and as a rule each of these issubjected to a specific pressure. As a function of the pressures setthere is an interaction of the tool elements in order to machine theworkpiece.

This applies especially also to so-called precision blanking devices inwhich the strips to be punched or the blanks are clamped between ablanking plate and a press plate and a blanking die and a pressure pad,which then move relative to one another. A corresponding precisionblanking device is described, for example, in European PatentApplication 85 981 05 31.5. In said publication it is apparent that thehydraulic devices for both sides of the press, i.e. for the upper andlower tools are extraordinarily complicated and are fixed for eachpress, i.e. cannot be changed.

A press of the above-mentioned type is known from DE 43 43 336 A1 as ahydraulic deep drawing device.

The present invention is based on the object of developing a press ofthe above-mentioned type in which the design of the press and thecontrol, in particular of the activity of the tools, is significantlysimplified and configured in a very variable fashion.

This object is achieved by virtue of the fact that the upper and lowerhydraulic plates are connected by means of built-in supports to form apiece of additional hydraulic equipment.

Consequently, the upper and lower hydraulic plates are combined to forma unit which can be inserted between, for example, a slide and the presslower part of the press. By means of the built-in supports, the upperand lower hydraulic plates are held apart, so that the hydraulic platescan each be secured separately to the slide and/or press lower part. Inorder to remove the built-in supports, the slide then merely needs tocomplete a travel movement, causing the built-in supports to bereleased.

Furthermore, there is also provision to connect a lower and an uppertool plate to form a tool packet, so that this tool packet can also behandled as a unit. This tool packet is placed as a unit between the twohydraulic plates, clamped tight, and the built-in supports are releasedby a travel movement of the slide. This means that not only the entirehydraulic device of the press, insofar as it affects the tool, but alsothe tool device itself can be handled very flexibly. An existing tool ortool module can be exchanged at any time for a different tool packetwith other tools. Basically, merely the base frame and the travel devicefor the slide always remain the same. All the other parts of the presscan be exchanged and replaced with other ones.

The chosen hydraulic plate has the advantage that the entire hydraulicsystem for controlling the tool is no longer fixed in the press itselfbut instead is separate from the actual press. The hydraulic plate canbe exchanged at any time and replaced with another hydraulic plate witha different hydraulic control system. In the preferred exemplaryembodiment there is even provision that the hydraulic plate alwaysremains unchanged while the actual hydraulic units can be insertedseparately into the hydraulic plate and therefore also exchangedseparately. Depending on the working method which is to be carried outon the corresponding press, the hydraulic units can be exchanged andreplaced with suitable units. Consideration has been given particularlyto the possibility of a plurality of hydraulic units being accommodatedone next to the other in the hydraulic plate, with the result that aplurality of work steps can be completed one after the other in a press.In this way, it is possible to machine a workpiece in this presssimilarly to a multiple tool or a multiple press. As a result, theentire work procedures are made significantly simpler and easier.

A hydraulic unit preferably has a working cylinder in which a workingpiston is arranged. This working piston is pressurized by an appropriatepressure medium or else a mechanical spring, for example; a controllableand adjustable pressure medium being, however, preferred. As a rule,hydraulic oil is suitable here, but, in particular, nitrogen is alsoconceivable.

In order to feed in the pressure medium, a plug-in pipe is providedwhich can be inserted into the hydraulic plate and forms a connectionbetween, for example, a hydraulic assembly and the working cylinder. Thehydraulic assembly itself may, in turn, be mobile so that it isindependent of the press. When nitrogen is used, the system is ofsimilar design, but there are then nitrogen containers located outsidethe plate.

Quick-release clamping devices, such as are described in European PatentApplication 86 81 01 76.7, are preferably used to secure the hydraulicplate to the press upper part and or the press lower part easily andquickly. As a result, the hydraulic plates can be exchanged veryquickly. In addition, there is provision to manufacture the hydraulicplates from aluminum, as a result of which there is considerable savingin weight.

It is particularly preferred that the upper and lower hydraulic platesbe connected to form one unit which can be inserted between, forexample, a slide and the press lower part of the press. By means ofcorresponding built-in supports the upper and lower hydraulic plates areheld apart so that the hydraulic plates can each be secured separatelyto the slide and/or press lower part. In order to remove the built-insupports, the slide then merely needs to complete a travel movement,causing the built-in supports to be released.

Furthermore, there is also provision to connect a lower and an uppertool plate to a tool packet so that this tool packet can also be handledas a unit. This tool packet is placed as a unit between the twohydraulic plates, clamped tight, and released by a travel movement ofthe slide of the built-in supports. This means that not only the entirehydraulic device of the press, insofar as it affects the tool, but alsothe tool device itself can be handled very flexibly. A tool which ispresent or a tool module can be exchanged at an time for a differenttool packet with other tools. Basically, merely the base frame and thetravel device for the slide always remain the same. All the other partsof the press can be exchanged and replaced with other ones.

Further advantages, features and details of the invention emerge fromthe following description of preferred exemplary embodiments and withreference to the drawing, in which

FIG. 1 shows a schematically illustrated side view of a press accordingto the invention;

FIG. 2 shows a plan view of the press in accordance with FIG. 1 withouta press upper part;

FIG. 3 shows a side view of the press in accordance with FIG. 1 in afurther installed position;

FIG. 4 shows a plan view of the press in accordance with FIG. 3 withouta press upper part;

FIG. 5 shows a plan view of the press lower part 3 and/or table clampingsurface;

FIG. 6 shows a plan view of a lower hydraulic plate;

FIG. 7 shows a partial cross section through a ball raceway inaccordance with FIG. 6 along line VII--VII;

FIGS. 8a-d shows a schematic illustration of the possible arrangementsof hydraulic units or nitrogen units within hydraulic plates;

FIG. 9 shows a cross section through a hydraulic unit or a nitrogen unitin the installed position in a hydraulic plate;

FIG. 10 shows a plan view of the hydraulic unit in accordance with FIG.9;

FIG. 11 shows a cross section through a safety coupling in the installedposition, illustrated in an enlarged view;

FIG. 12 shows a cross section through a further exemplary embodiment ofa nitrogen unit in the position of use;

FIG. 13 shows a schematic side view of a press according to theinvention;

FIG. 14 shows the end view of the press in accordance with FIG. 13.

FIG. 1 represents a press P in a schematic view, with only thoseelements which are important for the present invention. This includesessentially a slide 1 (press upper part) with which the press travel iscarried out. On the slide 1 there is a clamping-on plate 2 which may,moreover, also be an integrated component of the slide itself.

Opposite the slide 1 there is a press lower part 3 into which a tableclamping surface 4 is let. Provided in the table clamping surface 4 isan insert 5 which has a central opening 6 through which a punched orprecision blanked product or a punching can drop down.

Secured to the side of the press lower part 3 are two supportingbrackets 7.1 and 7.2 which each have a race 8 on which a piece ofadditional hydraulic equipment Q according to the invention is seated.Said equipment is composed of an upper hydraulic plate 9 and a lowerhydraulic plate 10 which are kept at a distance from one another bymeans of four built-in supports 11.

In order to insert the piece of additional hydraulic equipment Q intothe press P, the piece of additional hydraulic equipment Q is moved onthe race 8 into the region between the slide 1 and/or clamping-on plate2 and press lower part 3 and/or table clamping surface 4. Here, theupper hydraulic plate 9 and the lower hydraulic plate 10 are secured tothe clamping-on plates 2 and 4, which may be effected, for example, bymeans of a quick-release clamping device such as is described inEuropean Patent Application 86 81 01 76.7. As soon as the upperhydraulic plate 9 and the lower hydraulic plate 10 are secured, theslide 1 moves upward so that the built-in supports 11 are released. Theyare removed so that the space between the upper hydraulic plate 9 andlower hydraulic plate 10 is then free for the insertion of a toolpacket.

Moreover, two stops 12.1, 12.2 (see FIG. 2) can be seen on the lowertable clamping surface 4, which stops serve to preposition the piece ofadditional hydraulic equipment Q.

After the two hydraulic plates 9 and 10 have been positioned in thepress P, the supporting brackets 7.1 and 7.2 are turned over and theirheight is aligned so that a tool packet 13 can be introduced between theupper hydraulic plate 9 and lower hydraulic plate 10. Here, the toolpacket 13 also rolls on the races 8 of the supporting brackets 7.1 and7.2.

An upper tool plate 14 and a lower tool plate 15 are in turn separatedfrom one another by means of built-in supports 16. The upper tool plate14 is secured to the upper hydraulic plate 9 and the lower tool plate issecured to the lower hydraulic plate 10, which may in turn be carriedout by means of the above-mentioned quick-release clamping devices.Then, the press is moved apart, i.e. the slide is raised so that thebuilt-in supports 16 are released. Tools which interact are indicatedschematically at 17.

FIGS. 5 and 6 show the configuration of the table clamping surface 4 andthe lower hydraulic plate 10 in more detail. The two stops 12.1 and 12.2mentioned above are seated on the table clamping surface 4. Between thetwo stops 12.1 and 12.2 there is a push/pull chain 18 (indicated onlyschematically) with which the piece of additional hydraulic equipment Qcan be pulled over the table clamping surface 4. Here, the lowerhydraulic plate 10 rolls on two races 19.1 and 19.2 which are located inthe table clamping surface 4 and also span the openings 6.1 and 6.2. Atthe same time, T bars (described in European Patent Application 86 81 0176.7) engage in corresponding T grooves 20 which are used at a latertime to secure the lower hydraulic plate 10 on the table clampingsurface 4.

Further guidance of the lower hydraulic plate 10 is provided by means oflateral guide bars 21.1 and 2.2 which are arranged on the table clampingsurface 4.

FIG. 6 shows four drilled holes 22 in the lower hydraulic plate 10 inwhich the built-in supports 11 are plugged in the position of use. Inaddition, two ball raceways 23.1 and 23.2 are provided on the left andon the right and they are used for the later guidance of the tool packet13. Such a ball raceway is shown in more detail in cross section in FIG.7, one ball 24 being under the pressure of a corresponding pressuremedium.

In addition, there is in the lower hydraulic plate 10 a rectangularrecess 24 which is interrupted merely on both sides by means of onehydraulic roller block 25.1 and 25.2 in each case. This recess 24 isused for the insertion of hydraulic units 26 which are described later.The hydraulic unit 26 is supplied via a plug-in pipe 27 which is alsodescribed later. The hydraulic roller blocks 25.1 and 25.2 areconfigured in such a way that the tool packet 13 can be moved on them asfar as stops 28.1 and 28.2 on the lower hydraulic plate 10. Since thesehydraulic roller blocks are commercially available, a more detaileddescription will not be given. There are also hardened centeringbushings 29.1 and 29.2 which are provided on both sides of the recess 24in the lower hydraulic plate 10 and interact with preferably hydrauliccentering bolts 30.1 and 30.2 in the table clamping surface 4. The lowerhydraulic plate is positioned precisely by means of these hydrauliccentering bolts 30.1 and 30.2 before the built-in supports 11 areremoved.

The upper hydraulic plate, which is not shown in more detail, lookssimilar to the lower hydraulic plate 10, but is of significantly simplerdesign with respect to the positioning elements. It has merely the fourdrilled holes for receiving the built-in supports 11. In addition, ithas a rectangular recess corresponding to the recess 24 into whichcorresponding upper hydraulic units or nitrogen units are inserted.Corresponding plug-in pipes then in turn lead to the latter.Essentially, the alignment of the upper hydraulic plate 9 is effected bymeans of these built-in supports 11.

FIG. 8 shows various possible ways of arranging hydraulic units 26 andnitrogen units in the recess 24 in the upper and lower hydraulic plates9 and 10. In FIG. 8a there are only four units 26 inserted, in FIG. 8bfive units, in FIG. 8c six units and in FIG. 8d seven units. It ispossible either to insert filler elements between them, which elementssupport the individual units 26 on one another or else open spaces mayremain, through which punchings or the products of punching-outoperations pass into the lower region of the machine and are moved awayfrom there. In this way, a press is produced with individual ormultistage tools. Any desired arrangement is possible.

Each unit 26 which is inserted into a recess 24 in the lower or upperhydraulic plates 10 and 9 has a working cylinder 30 in which a workingpiston 31 slides. These working cylinders 30 and working pistons 31perform the inner tool functions of the press and/or its functionswithin the tool packet 13, such as for example provision of an abutmentduring precision blanking, stripping, ejection etc. This takes placeoutside the actual tool packet 13.

The working pistons 31 can be activated by means of pressurized oil,compressed air, nitrogen or by means of mechanical springs. In thepreferred exemplary embodiment, pressurized oil is used. Thispressurized oil is fed via the plug-in pipe 27 into the working cylinder30.

32 designates drilled holes through which corresponding attachment meansare inserted and by means of which the hydraulic unit 26 can be securedin the recess 24.

According to FIG. 11, all the plug-in pipes 27 are equipped with safetycouplings 33 or safety diaphragms which prevent excess hydraulicpressure in the event of a hydraulic connection becoming inadvertentlydetached from the plug-in pipe 27, for example.

The various units 26 also include an appropriate mobile assembly bymeans of which the working cylinders 30 are supplied with pressurizedoil, compressed air or nitrogen. This assembly is preferably anindependent unit which is independent of the press.

In addition, a valve control block should be provided between theassembly and the corresponding connections of the units 26, it beingpossible for each working cylinder 30 in the individual units 26 to beset and regulated separately by means of said block. Each workingcylinder 30 thus has its own control loop, it being possible to regulatethe pressure/force adjustment in an infinitely adjustable fashion. Thispressure is regulated in accordance with the functions of the units 26,any desired possibilities being conceivable here.

According to FIG. 12, a unit 26 which has two working cylinders 30.1 and30.2 which are filled with nitrogen is inserted into a hydraulic plate9/10. Two working pistons 31.1 and 31.2 are pressurized by means of thenitrogen, causing corresponding connection parts 34.1 and 34.2 in thetool plate 14/15 to be pressurized. These then transmit their movementand/or movement capability to a tool module 35.

FIGS. 13 and 14 indicate a table clamping surface 4 on which the lowerhydraulic plate 10 with the recess 24 is seated. On this hydraulic plate10 there is, in accordance with FIG. 14, the lower tool plate 15 and thetool module 35.1. Over the latter there hangs an upper tool module 35.2on an upper tool plate 14 which is in turn attached to the upperhydraulic plate 9.

Punchings can drop past the side of the lower tool plate 15, the lowerhydraulic plate 10 and the table clamping surface 4 or else drop throughthe recess 24 and/or the central opening 6 and pass along various baffleplates 36 to a conveyor 37.

What is claimed is:
 1. A precision blanking press, comprising: a pressupper part (1); a press lower part (3) associated with the press upperpart (1); a tool (17) located between the press upper part (1) and presslower part (3); and an upper hydraulic plate (9) arranged between thetool and the press upper part (1) and a lower hydraulic plate (10)arranged between the tool and the press lower part (3), wherein theupper and a lower hydraulic plates (9, 10) are connected by means ofbuilt-in supports (11) to form a piece of additional hydraulic equipment(Q) wherein the supports are released from the plates by movement of thepress upper part by means of quick release devices to form a space toreceive a tool packet.
 2. The press as claimed in claim 1, wherein theadditional hydraulic equipment comprises a valve block and a mobilehydraulic assembly.
 3. The press as claimed in claim 1, wherein an upperand a lower hydraulic plate (14, 15) are connected by means of built-insupports (16) to form the tool packet (13).
 4. The press as claimed inclaim 1, wherein at least one of the hydraulic plates (9, 10) has arecess (24) for receiving a hydraulic unit (26).
 5. The press as claimedin claim 4, wherein the unit (26) has a working cylinder (30) in which aworking piston (31) is arranged.
 6. The press as claimed in claim 5,wherein a plug-in pipe (27) for feeding in a pressure medium opens intothe working cylinder (30).
 7. The press as claimed in claim 1, whereinthe hydraulic plates (9, 10) are connected to the press upper part (1)and the press lower part (3) by means of quick-release clamping devices.8. The press as claimed in claim 7, wherein a clamping surface (4) isarranged between the press upper part (1) and press lower part (3) andhydraulic plates (9, 10).
 9. The press as claimed in claim 3, whereinthe lower hydraulic plate (10) has lateral ball raceways (23) forguiding the lower hydraulic plate (15).